Geology for Global Development


This guest post was contributed by a scientist, student or a professional in the Earth, planetary or space sciences. The EGU blogs welcome guest contributions, so if you’ve got a great idea for a post or fancy trying your hand at science communication, please contact the blog editor or the EGU Communications Officer Laura Roberts Artal to pitch your idea.

Bárbara Zambelli Azevedo: Urban Geology and Underground Urbanisation

Today is World Cities Day, and the week of our annual conference exploring the role of geoscience in sustainable cities. To mark these events, our newest contributor, Bárbara, writes on urban geology and underground urbanisation.

Underground urbanisation is not a brand new topic, it has been discussed for more than 100 hundred years! But, why is it important to think about underground urbanisation? According to an UN report, the current world population of 7.6 billion is expected to reach 8.6 billion in 2030 and 9.8 billion in 2050. In addition, the percentage of the world’s population living in urban areas is growing steadily. In 1960 it was 34% of the total population and over 54% in 2016. To this extent, locating this increasing population in urban areas is becoming more and more  challenging. Cities’ territorial expansion is limited by the natural environment constraint and farmland protection. Although, advances in tunnelling and excavating technology and increases in land prices have resulted in underground urbanisation becoming a more feasible and economical option.

When it comes to Brazil….

After researching in different databases (both Brazilian and international) about the theme, little information was found. However, two PhD theses caught my attention. The first one is called “Urban Geology of São Paulo’s Metropolitan Region”, of 1998. This thesis presents a geological description of the area followed by the history of urbanisation of the biggest Brazilian city. The author dedicates one chapter only for “Urban Geology”, where he highlights the importance of geological, geomorphological, geotechnical and hydrogeological knowledge in the process of urbanisation. This work mapped the potential areas for landslides and floods in São Paulo’s metropolitan area. Although this work was presented on the relation between geology and urban planning, it was classified in the field of “sedimentary geology”.

Sao Paulo, Brazil

The second thesis was written by an urban planner in 2009 and it is called “Underground Urbanism”. The author discusses the ethical arguments for land use and occupation. She endorses the densification of cities by expanding downwards, enabling different activities to overlap. By doing this, the use of the ground is maximised without the requirement of skyscrapers. Her work found no urbanistic nor economic or technological restrictions for the use and occupation of the subsurface upon a indoor city.

An International Scenario

In 2007, the Deep City research program was launched , a partnership between Switzerland and China. It divided underground resources into four types: space, geomaterials, groundwater and geothermal energy. In this manner, developing the underground means to create new alternatives for transportation, utility infrastructures, new sources of mineral resources and renewable thermal energy.

It noted :“The Deep City provides a strategic framework to analyse the synergies and conflicts between these underground resources in the urban planning process, in order to align underground urbanisation with a sustainable development paradigm”  [Read more here, here, and here].

In China, Suzhou City was chosen as a pilot project based on its higher score of “Deep City applicability” over other Chinese cities (Beijing, Nanjing, Suzhou, Shanghai). The Suzhou provincial and municipal governments assisted by gathering resource database, with administrative consultation and the development of an information system to help decision-making. The authors gathered and bench-marked the most desirable practices in management and administration of underground resources, looking at seven cities (Helsinki, Singapore, Hong Kong, Montreal, Minneapolis, Tokyo and Shanghai).

Suzhou City (China)

After analysing many different factors for the supply side such as geo-risks, soil thickness, aquifer outflow, among others, and for demand side like civil defence, commercial land prices, land use type, etc. The authors highlight that an integrated underground use and management can only be possible if all the city departments work together into decision-making.

Subsurface planning is a multidisciplinary task, so geoscientists will be required to work together with other professionals (e.g., architects, urban planners and engineers), as well as local and national governments. If underground urbanisation was used more in big cities worldwide it could help to address sustainable development in terms of optimising the land use, conserving supplies such as groundwater, geothermal energy, space and mineral resources. It could help to achieve some of the UN Sustainable Development Goals, such as SDGs 6, 7, 10 and 11.

The field is really vast and open and there are a lot of opportunities to explore!

Jesse Zondervan’s #GfGDPicks (Oct 2017): Tsunami risk in Geneva, storms in Mumbai, floating runways in Fiji, a river with legal rights, #SciComm

Each month, Jesse Zondervan picks his favourite posts from geoscience and development blogs/news, relevant to the work and interests of  Geology for Global Development . Here’s a round-up of Jesse’s selections for the past two weeks:

If you thought we were safe from Tsunamis in Europe, think again. I was surprised to find out Geneva experienced a Tsunami in 563 triggered by a mudslide. On a similar tack, a recent study at the Lamont-Doherty Earth Observatory concludes the storm surge risk for Mumbai may result in a terrible disaster.

As well as better understanding the nature of the risks we face, an important aspect of disaster risk reduction (DRR) is communication. Academics from King’s College London report on a hazards-themed workshop they gave in Malawi. Read more about how they hope to reach >2000 students.

Meanwhile, Fiji suffers from floating airport runways due to the rise in sea-level and Dr Nick Mount explores Colombia for the question: Can a river have legal rights?

There is much more to explore below so go ahead! I’ll end with the following question:

What makes you curious? What would you like to know about geology and global development?

Please do leave a reply!

Some great articles came out around the International Day for Disaster Reduction:

Coastline of Mumbai, India

Climate Change Adaptation & Environmental:

Upcoming opportunities:

Check back next month for more picks!

Follow Jesse Zondervan @JesseZondervan. Follow us @Geo_Dev & Facebook.

Introducing Our New Authors (4) – Bárbara Zambelli Azevedo

We’ve been introducing you to a couple of new faces on the GfGD blog, bringing fresh ideas and perspectives on topics relating to geoscience and sustainable development. We’re delighted to have their input, and look forward to their posts. Today we interview the final of our four new recruits, Bárbara Zambelli Azevedo.

Hello! Could you introduce yourself?

I finished my graduation in Geological Engineering at the Federal University of Ouro Preto, Brazil, in June of this year. As a student, I’ve spent one year doing an academic exchange at University College Cork, Ireland. In addition, I was part of the Excursionist and Speleological Society (SEE-EM/UFOP) since 2012, having worked in over 150 caves!

During the past 6 years, I had the opportunity to visit, travel, study and work in more than 20 countries, in America, Africa and Europe. After that, my interest on the relationship between geology and society was significantly enhanced.

Recently, I saw the opportunity of getting involved with GfGD as a science communicator. I got really excited about it! As I see, science communication is about shortening distances by connecting people with the same interests, building a strong network worldwide. I’m passionate about travelling, photography, cooking, engaging with other cultures and experiencing other ways of living. I love to spend time outdoors, hiking and climbing as much as I can.

How did you find out about GfGD?

The first time I heard about GfGD was while researching for my graduate thesis, at the end of last year. Before that, I’d experienced some different areas within geology. I was tutoring structural geology for one semester, and have done some research on geochronology, speleology, field geology and geological mapping. When I came back from Ireland and started to write my thesis, I decided to stray from classical geology to explore  “social geology” , the overlap between “geology” and “development”. At this moment I came across the GfGD blog, with many useful open access papers and posts on different topics. I also heard about the 5th GfGD Annual Conference. After finishing my thesis, I got in touch and decided to get involved with this charity!

Can you give us a glimpse of your grad thesis?

For sure! The title of my thesis is “The role of geology in Ouro Preto’s development”. It tells the history of Ouro Preto, its occupation, the relationship with the geology in its very beginning and also today. The data collected showed that many problems faced by the city are due to chaotic urbanisation since the 1960’s and the historical economic dependence of the mining sector. Supported by the papers Stewart & Gill (2017) and Gill (2017), I proposed some actions to be taken by geologists working at Ouro Preto’s public administration to achieve some of the 17 UN Sustainable Development Goals. If you want to know more, please contact me, or come along to the 5th GfGD Annual Conference where I’ll be giving a micro-presentation on my work!

What themes will you be writing about?

Widely, as expected, I would say that I’m keen on writing about how geoscience can address the UN Sustainable Development Goals. I would love to learn more about hydrogeology, climate change and urban geology. In this sense, I’m looking forward to the 5th GfGD Annual Conference on “Cities: Opportunities and Challenges for Sustainable Development” to see what pops up from there. I expect to produce a range of article types, including paper reviews, free online resources and data, study cases, among others.

Ideas for the future?

Presently, I have plans to do a Master in Hydrogeology next year. Since none of my field experience is directly related to hydrogeology, I also hope to engage in field work for a while before that. Ideally, I would love to work towards  poverty relief, gender equality, access to clean water and sanitation using hydrogeology, geoscience education and science communication in as many parts of the Global South as I can. I’m also eager to keep on writing posts for GfGD blog!

You can contact Bárbara via geol.zambelli[at]

**This article expresses the personal opinions of the author (Bárbara Zambelli Azevedo). These opinions may not reflect an official policy position of Geology for Global Development. **

Robert Emberson: Soil Erosion and Sustainable Development

Over the last few weeks we’ve introduced you to some new faces on the GfGD blog, including Robert Emberson, Heather Britton and Jesse Zondervan. Today, Robert (based in Victoria, Canada) writes on the connections between soil erosion and sustainable development, and poses the question – is soil one of our most threatened resources? 

When we talk about sustainable energy sources, most of the time we’re referring to renewable sources of electricity and heat. Geothermal, solar, wind or waves – these are all sources of energy that are, within practical limits, not exhausted by our use. However, all living species need more than just electricity and heat as energy; we need food to sustain us.

The vast majority of food for humans requires agriculture, whether vegetable crop or grazing species. Agriculture depends completely on fertile soil to succeed, but we often don’t think about soil as a resource that really matters. Crucially, however, the rate at which soil forms is vastly outpaced by the rate it erodes away in modern farming. For all intents and purposes, soil is a non-renewable resource, like fossil fuels.

A recently published UN study has highlighted this, estimating that 24 billion tons of fertile soil is lost annually every year – primarily in sub-Saharan Africa. The implications for sustainable production of food are obvious, with some studies suggesting we only have an average of 60 years’ worth of harvests left under the current practices.

We shouldn’t ignore the inherent potential of this crisis to exacerbate existing economic inequalities, too; according to the study authors “critically unbalanced land productivity trends in African cropland and grasslands are particularly concerning given expected population growth.”  This, in fact, highlights the most worrying trend; even as soil is eroded away, and the amount of cropland dwindles, the global population increases apace, with 9 billion mouths to feed estimated by 2050.

Farming in Uganda (Source: GfGD)

Moreover, the UN study emphasises that degradation of soil and loss of agricultural land increases the competition for already-scarce resources, which could lead to mass migration or social instability, further increasing the difficulty of implementing sustainable solutions.

So how has the problem become so acute? It is useful to first explain how soil erosion occurs naturally, before thinking about how humans have impacted the natural cycles. Roughly, natural soils form as the result of chemical breakdown of underlying bedrock, supplemented by organic matter decaying from dead plants and animals. In a stable system, the rate at which soils are produced is in balance with the rate at which water washes away surface material during floods and storms.

In some parts of the world, where warm, wet, conditions are ideal for plant growth and chemical reactions, soil can grow extremely fast – as much as 2.5mm per year, although the global average is nearer to 0.1mm per year.

Water is the primary agent that erodes the soil. Whenever rain falls, droplets can dislodge material, and these can be washed away downhill or carried in floodwaters over landscape. It’s no surprise, then, that soils through which water can more easily infiltrate are less likely to lose material to overland flow. However, humans have fundamentally altered this balance.

Natural forests allow water to infiltrate into soil quickly, but without root systems and porous soil this can be much lower. For example, in Wales scientists demonstrated that forested plots had infiltration rates 67 times faster than sheep pastures. Agricultural land is similar, or can be worse; if there are no crops to bind the soil together for some parts of the year, or if ploughing churns up the soil and allows material to be easily washed away, topsoil can be severely depleted in a single flood.

These two factors – lack of plant cover, and extensive tillage – are hallmarks of high intensity farming globally, but as the UN study points out, while this kind of farming has increased productivity over the last decades, it is increasingly unsustainable. Addition of fertiliser has increased the productivity, but masked the degradation of arable land. Moreover, in some regions it creates a viscous cycle, where loss of productive land leads to deforestation to access untapped soil.

Forests are key buffers against many slow and fast moving disasters; they can limit flooding, by encouraging water to infiltrate rather than running over landscape, and in doing so can allow more water to reach aquifers – thus limiting drought later. They also serve important roles in stabilising hill-slopes against landslides, and slow desertification. Given how long it takes for forest to regrow, it seems clear that the impact of soil loss will be felt for years to come.

So what can be done to prevent it? And how can geologists act to help address the problem, particularly how we can still achieve sustainability goals in the face of the rapid loss of life-giving topsoil? An integrative approach is certainly important. Soil is the interface where life, at a microbial and macro-scale, coexists with physical and chemical processes in the bedrock. Understanding how all of these fit together is crucial to build a clearer picture of the at-risk soil.

Sustainable rehabilitation of agricultural land has been achieved at a wide scale in some countries, like Ethiopia. Surface process geologists could help by producing maps of local and regional propensity for erosion, to help guide these efforts. Scientists from the Kenya-based World Agroforestry Centre have been hard at work producing for the first time maps of soil chemistry and health across sub-Saharan Africa, and these should similarly help to more efficiently utilise the soil for particular crops, and aid in crop choice for a given location, if appropriately combined with crop biology assessments.

The authors of the UN study explain that increasing the efficiency of agriculture would certainly alleviate some of the stress on croplands. Improvements in efficacy can be found at different points throughout the food supply chain; for example, the authors write that:

“Eliminating food waste would reduce the projected need to increase the efficiency of food production by 60 per cent to meet expected demands by 2050”.

Meat uses five times as much land for a given nutritional intake than the comparable vegetable option, so reducing the intake of meat, along with other nutritionally inefficient crops (like soy and palm oil) would distinctly reduce the amount of cropland needed to feed 9 billion people. These solutions are politically sensitive, of course, but scientists can make informed decisions about their own food choices, and encourage others to do the same.

Above all, given how important soil is to land surface processes, many geologists could ask themselves which aspects of their own knowledge might help alleviate this significantly under-reported problem. While we have alternative, renewable energy sources to turn to instead of fossil fuels, we don’t yet have an alternative to soil, and as such it’s perhaps imperative to think about soil as one of our most threatened resources.

Robert Emberson is a science writer, currently based in Victoria, Canada. He can be contacted via Twitter (@RobertEmberson) or via his website (

**This article expresses the personal opinion of the author. These opinions may not reflect official policy positions of Geology for Global Development.**